Every now and then Texans running back Arian Foster will hear a voice on the sidelines.

“I’m coming after you,” the voice says.

But it’s not an imaginary voice at all. It’s been his backup Ben Tate being very honest that he is right on the heels of the NFL reigning rushing leader.

Foster ranks eighth in the league with 656 yards and Tate ranks ninth with 623 yards on the ground. The Texans are benefiting from what seems to be a very healthy competition with Foster and Tate combining to become the most formidable 1-2 running back punch in the NFL this season.

Their success running the football as a duo has been instrumental in the AFC South-leading Texans having the most successful season so far in franchise history at 6-3 and riding a three-game winning streak into Sunday’s road game at Tampa Bay.

“It’s fun to watch,” Texans quarterback Matt Schaub said of the Foster and Tate. “It’s fun to watch those guys, especially after the fact.”

Their success as a duo has been something that no one could have predicted coming into the season. Foster was the known commodity after bursting onto the scene last season to lead the league in rushing.

Tate, a second-round draft pick out of Auburn in 2010, was very much an unknown after missing all of his rookie season after suffering a serious ankle injury on the first carry of his first preseason action last year.

But with Foster hindered by a bothersome hamstring injury early in the season, Tate wasted little time showing that he wasn’t going to be your ordinary situational backup. He is an impact player and that was obvious when he came out of the gate with back-to-back 100-yard rushing performances to lead the Texans in Foster’s absence.

Once Foster returned and got into his groove there were those who wondered how Tate would handle dealing with far fewer carries. Then there were those who wondered just how potent the offense would be with two backs able to for 100 at anytime.

Who knew there would be enough carries for both to be 100-yard rushers in the same game? But with star receiver Andre Johnson sidelined with a hamstring injury the last month, the Texans have played to their strength and that’s moving the football on the ground.

The duo of Foster and Tate have rushed for 100-plus yards each in two of the last three games, including Sunday’s 30-12 win over the Cleveland Browns when Foster ran for 124 yard and Tate added 115 yards and 9.6 yards per carry.

“That means so much,” said Texans tight end Owen Daniels. “Usually it’s just a guy spelling someone for a couple plays and hoping they can hang in there and have a good run or two. But you got two good backs with a little bit different styles. It’s a good one-two punch, that’s for sure.”

And that never seems more obvious than in fourth quarters when running backs are usually slowing down, Foster and Tate are still charging hard and making explosive plays because they are fresher from split carries earlier.

“Arian would probably answer he wants the ball every snap because he’s a competitive guy and a hell of a player. It just makes the team stronger,” said Texans coach Gary Kubiak, whose team ranks second in the NFL in rushing. “More guys contributing makes the team stronger, continues to push everybody to a new level and that’s what we’re trying to do right now.”

Part of what seems to make this work is unselfishness on the part of Foster, who is certainly leaving a lot of yards on the table for the betterment of the team and likely his long-term health. Foster is also in a contract year and headed for his first major payday and not being able to pad his stats could seem risky.

But instead of worrying his money, Foster seems content to keep the focus on what both backs bring to the table makes the Texans so potent offensively. Unlike most duos, they are very similar in style as explosive backs, who are capable of either running through tackles or running around them.

“I think we are both good runners, we both see holes well,” he said. “And our O-line when they control the line of scrimmage it makes our jobs that much easier.”

Texans running back Derrick Ward (credit: Getty Images)

The duo, along with third back Derrick Ward try to make things easier for each other by being each others’ eyes on the field and on the sidelines. You can often see the three huddled together on the sidelines engaged in intense conversations.

“We like to be each others eyes, as well as Derrick Ward out there,” Foster said. “Every time I come off the field I talk to him to see what he sees, see what he feels because we are both going through the same thing. So it’s good to get little bits of information. I try to share everything with him and vice versa. It’s a good thing to have.”

As for any type of petty jealousy that can crop in when you have two high-performing athletes at the same position? Both insist that doesn’t exist in the Texans backfield.

“We’re both competitors. It’s friendly competition,” said Tate, who leads the NFL with an average of 5.7 yards per carry. “It doesn’t really get too much better than that. Like I said, we’re both competitors at heart. We’re both pretty good running backs, so you got to compete and it’s only going to help the team.”